Leases (Details) $ in Thousands	1 Months Ended	3 Months Ended		9 Months Ended
	Feb. 28, 2019 USD ($) ft²	Sep. 30, 2019 USD ($)	Sep. 30, 2018 USD ($)	Sep. 30, 2019 USD ($) item	Sep. 30, 2018 USD ($)	Dec. 31, 2018 USD ($)	Nov. 30, 2017 ft²
Lessee, Lease, Description [Line Items]
Loss on lease termination		$ 306
Rent expense			$ 204		$ 682
Area leased, sublease agreement | ft²	21,056						33,019
Total renovation and improvement costs	$ 1,472			$ 555
Number of lease financing arrangements | item				2
Finance lease term				4 years
Operating Leases:
Gross cost		5,007		$ 5,007		$ 3,609
Accumulated depreciation		(2,153)		(2,153)		(1,322)
Operating lease right-of-use assets		2,854		2,854		$ 2,287
Other current liabilities		507		507
Other liabilities		3,686		3,686
Total operating lease liabilities		4,193		4,193
Operating Leases
Lessee, Lease, Description [Line Items]
Total future total rent payments	$ 3,538
Operating Leases:
Gross cost		5,213		5,213
Accumulated depreciation		(331)		(331)
Operating lease right-of-use assets		$ 4,882		$ 4,882
Financial position		us-gaap:OtherLiabilitiesCurrent		us-gaap:OtherLiabilitiesCurrent
Financial position		us-gaap:OtherLiabilitiesNoncurrent		us-gaap:OtherLiabilitiesNoncurrent